Display apparatuses with sequential scrolls of advertisement sheets are well known and broadly used. Such apparatuses allow advertisers to share display spaces and owners of the spaces to profit from the rental of these spaces.
A well-known type of these scrolling display apparatuses comprise a pair of parallel rollers spaced from one another. A film supporting a sequence of advertisement images is unwound from the first roller to be wound onto the second roller in a first displaying sequence. Once the film has been completely unwound from the first roller, the sequence is reversed to wind the film onto the first roller.
Although such display apparatuses are relatively simple, the nonuniform sequence of the image display is problematic. More specifically, the end images get about half as much exposure as the in-between images of the film. Also, when the film reaches an end of the sequence, the penultimate image is shown twice in a three-display sequence. Accordingly, the attention span of an observer may be shortened by the lack of novelty in the displays he observes. Also, it is known that the attention span is relatively short, and it is therefore preferable to squeeze as many different images as possible into this attention span, rather than showing a repeat of a same image.
Accordingly, other types of display apparatuses have been provided with continuous display sequences. For instances, U.S. Pat. No. 5,276,987, issued on Jan. 11, 1994, to Honse, discloses a display system for advertisement sheets having a storage rack with an entrance and an exit. A belt drive entrains a first display sheet from the exit in a circuitous pathway to a display area. Thereafter, the first display sheet is returned to the entrance of the storage rack, behind the other sheets. This display system operates in a “first-in, first-out” fashion, whereby all other display sheets will have to be displayed prior to the first display sheet being entrained by the belt drive.
In such display systems, the display sheets must be installed onto the existing belt drives. The display sheets are, for instance, glued to the drives, or have connectors (such as zipper, Zip-lock™ mechanisms) glued thereto for subsequent installation on the drive.
Unfortunately, the bonding of the connectors to the display sheets or of the display sheets to the drive is not very convenient, especially if the bonding takes place on site. For instance, the curing time of bonds or glues is typically 24 hours at room temperature before exposure to lower temperatures. Accordingly, the bonding of the advertisement sheet to the connectors cannot be performed on outdoor sites below certain temperatures. In cases where connectors are used, it is possible to supply additional sets of connectors to be bonded to the advertisement sheets prior to the on-site installation. However, this represents additional costs, and hence is not an optimal solution considering that the advertisement sheets are relatively cheaper in price than the connectors. It is possible to lessen the strength of the bond or shorten the curing time, but this may ultimately result in the advertisement sheets dislodging from the display system, and cause inoperability of the display system.
Accordingly, because of the inconvenience provided by the use of glue or bond fixing the connectors to the advertisement sheets, some advertisement sheets of display apparatuses go unchanged in some cooler countries during the cooler periods. Therefore, such display apparatuses are less appealing to some products having shorter lifespans, if advertisement contracts are struck with relatively long terms (e.g., six months) that are scheduled to avoid advertisement sheet changes in the cooler weather.
Another drawback of display apparatuses is the premature ripping of advertisement sheets. The advertisement sheets are typically of a nonextendible material, and the connectors attaching the advertisement sheets of the display apparatus keep the advertisement sheets taut. The advertisement sheets are displaced in a circuit in which they follow both straight and arcuate paths. In the arcuate paths of the circuit, the distance between the connectors at opposite ends of an advertisement sheet often varies slightly, thereby causing unwanted tension or ballooning in the advertisement sheet. This unwanted tension can cause the advertisement sheet to rip, thereby causing the inoperability of the display apparatus. This situation is likely to occur during cooler periods, in which the advertisement sheets contract due to exposure to cold temperatures. Considering the inefficient change of advertisement sheets: as set forth above, the ripping of an advertisement sheet in cold weather is likely to result in an extended downtime of the display apparatus.